1. Field of the Invention
This invention relates to a viscous fluid dispenser, and more particularly to a viscous fluid dispenser which is adapted to dispense a desired mount of viscous fluid such as toothpaste through a nozzle therefrom by means of a pumping mechanism incorporated therein.
2. Description of the Prior Art
A conventional dispenser for dispensing viscous fluid such as toothpaste is generally constructed in such a manner as shown in FIG. 1. More particularly, the conventional dispenser includes a cylindrical body 100 opened at upper and lower ends thereof, a movable bottom lid 102 liquid-tightly slidably fitted in the lower open end of the cylindrical body 100, a partition plate 104 arranged so as to close the upper open end of the cylindrical body 100 and formed with a suction hole 106, an elastic dome member 108 provided above the partition plate 104 in a manner to cover the partition plate 104, and a cap 110 threadedly fitted in the upper end of the cylindrical body 100 so as to cover the dome member 108 and formed on a side thereof with a discharge port 112. The dome member 108 has a dome chamber defined therein, and the cap 110 has a push button 114 formed on an upper portion thereof for pushing the dome member 108. The dispenser also includes a fixing plate 116 formed with a first opening 118 communicated with the suction hole 106 of the partition plate 104 and serving as an entrance to the dome chamber of the dome member 108 and a second opening 120 communicated to the discharge port 112 of the cap 110 and serving as an exit of the dome chamber of the dome member 108. The fixing plate 116 acts to fixedly mount the dome member 108 in the cap 110. Further, the dispenser includes a valve mechanism which comprises a valve body 122, a first check valve 124 arranged at the first opening 118 of the fixing plate 116, and a second check valve 126 arranged at the second opening 120, each formed integral with the valve body 122. In addition, the dispenser includes a stopper 128 for closing the discharge port 112 of the cap 110 and an overcap 130 for covering the cap 110.
In the conventional viscous fluid dispenser constructed as described above, the overcap 130 is removed. Then, when the elastic dome member 108 is pressed by pushing the push button 114 and then releasing the push button 114 from the pressing, a negative pressure is applied to an interior or the dome chamber for the dome member 108 to open the first check valve 124, resulting in a predetermined amount of toothpaste being supplied from the cylindrical body 100 through the suction hole 106 to the dome chamber of the dome member 108. This causes a negative pressure to be applied to the interior of the cylindrical body 100, so that the bottom lid 102 may be slidably raised. Then, re-pushing of the push button 114 causes the second check valve 126 to be opened while keeping the first check valve 124 closed, resulting in the toothpaste supplied to the dome chamber of the dome member 108 being discharged through the discharge port 112.
Unfortunately, as is apparent to those skilled in the art from the foregoing, the conventional viscous fluid dispenser has the disadvantage of requiring a large number of parts, resulting in it being complicated in construction and being troublesome to assemble.
Accordingly, it would be highly desirable to develop a viscous fluid dispenser which is capable of being simplified in construction, thus significantly decreasing the number of parts required and being readily assembled.